Alkyl or halo substituted tetrahalofluorans

ABSTRACT

6&#39;&#39;-((C2H5-)2-N-)SPIRO(PHTHALAN-1,9&#39;&#39;-XANTHENE)   WHEREIN EACH R1, R2, R3 OR R4 IS HYDROGEN, AN ALKYL RADICAL HAVING 1 TO 4 CARBON ATOMS OR CHLORINE AND AT LEAST ONE OF SAID R GROUPS IS AN ALKYL RADICAL OR CHLORINE. 3-(O=),4,5,6,7-TETRA(CL-),1&#39;&#39;-R1,2&#39;&#39;-R2,3&#39;&#39;-R3,4&#39;&#39;-R4, A CHROMOGENIC MATERIAL OF NORMALLY COLORLESS FORM IS DISCLOSED HAVING THE STRUCTURAL FORMULA:

United States Patent 3,642,828 ALKYL 0R HALO SUBSTITUTEDTETRAHALOFLUORANS Sheldon Farber and Arthur John Wright, Dayton, Ohio,assignors to The National Cash Register Company, Dayton, Ohio NoDrawing. Filed Nov. 3, 1970, Ser. No. 86,641 Int. Cl. C07d /34 US. Cl.260343.3 2 Claims ABSTRACT OF THE DISCLOSURE A chromogenic material ofnormally colorless form is disclosed having the structural formula:

wherein each R R R or R is hydrogen, an alkyl radical having 1 to 4carbon atoms or chlorine and at least one of said R groups is an alkylradical or chlorine.

This invention relates to colorless, but colorable fluoran dyes for usein pressure sensitive record material. More specifically, this inventionrelates to tetrahalo-fluoran dyes.

Throughout this application, it is to be understood that the fluorandyes are substantially colorless until reacted with an acidic material.

Heretofore, some of the pressure sensitive, mark-forming systems of theprior art employed fluoran dyes which are substantially colorless inform when in liquid solution, but which are connected to colored formsupon reactive contact with acidic material. Ofter, there are problemswith the intensity and hue of these colored forms. For example, colorinstability on exposure to light frequently occurs.

Colorless, but colorable tetrahalo-fluoran dyes now have been found. Thetetrahalo-fiuoran dyes of this invention have improved lightfastnessqualities, i.e., improved fade resistance.

Pressure sensitive, mark-forming systems of the prior art include amarking system of disposing on or within sheet support mate-rial,mutually reactant but unreacted mark-forming components and a liquidsolvent in which each of the mark-forming components is soluble. Theliquid solvent is present in such form that it is maintained isolated bya pressure rupturable barrier from at least one of the mark-formingcomponents until an application of pressure causes a breach or ruptureof the barrier in the area delineated by the pressure pattern. Themarkforming components thereby are brought into reactive contact,producing a distinctive mark.

The tetrahalo-fiuoran dyes of this invention having chromogenicproperties can be incorporated in a web or coated onto the surface of aweb to provide a manifolding unit, which is useful in carrying outmethods of marking involving reactive contact with color activatingmaterial to yield colored reaction products in areas where marking isdesired.

3,642,828 Patented Feb. 15, 1972 The colorless, but colorabletetrahalo-fluorans of this invention are represented by the formula:

CH3 H H H H CH3 CH3 H H H H CH3 CH3 H CL... CH3 H H CH3 H CH3 I]: O1

The tetrahalo-fluorans of this invention can be produced by any methodknown in the prior art. Generally, tetrachloro-phthalic anhydride isreacted with a diethylamino phenol to give tetrachloro-benzoic acid.This is then reacted with a phenol or naphthalene in the presence ofsulfuric acid to yield the desired fluoran. Prior art processes aredescribed in US. Pat. 3,501,331 and Beilsteins Handbuch der Organischem*Chemie, copyright 1934 by Julius Springer in Berlin, volume XIX, pages348-349.

A composition of matter is disclosed which comprises a colored productof chemical reaction having a resonant chemical structure and producedby contact of a coloractivating material with one of the above-mentionedchromogenic compounds. The color-developing or activating material is anacidic substance useful for converting the chromogenic compounds tocolored forms.

The method of marking of this invention, i.e., the method of developinga colored material from substantially colorless or slightly coloredchromogenic compounds, comprises providing a chromogenic compoundselected from among the above-mentioned compounds and bringing suchchromogenic compound into reactive contact with an acidiccolor-activating substance, in areas where marking is desired, toproduce a colored form of the chromogenic compound by the actionthereupon of the acidic substance.

Acidic materials employed in this invention can be any compound withinthe definition of a Lewis acid, i.e., any electron acceptor. Preferably,acidic organic polymers such as phenolic polymers are employed as theacidic material. The novel chromogenic materials exhibit the advantageof improved color stability when they are reacted with such phenolicpolymers. Solution formation of solid particles of the polymericmaterial in a solvent system with the substantially colorlesschromogenic compounds permits penetration of the colored reactionproduct into a porous support sheet, e.g., paper, so that the coloredform of the chromogenic material is absorbed into the body of the sheetand is not merely on the surface of the sheet. The absorption featureprovides protection against erasure of recorded data by attrition of thesurface of a record sheet.

In a two-sheet unit, the bottom surface of the overlying sheet issupplied on the surface or near the surface with a multiplicity ofminute pressure-rupturable microcapsules containing a solution of thesubstantially colorless, chromogenic component. An acidic component,such as a acid clay or a phenolic polymeric material lies within thelower web or undersheet or upon the upper surface of the lower web orundersheet. A colored mark is made by the use of a stylus, a typecharacter, or other pressureexerting means applied to the two-sheet unitmanifold.

The encapsulated solution is released on the event of rupture of thecapsules in writing operations. The released solution is transferredfrom the overlying or base-sheet to the receiving surface of theunderlying sheet in conformance with the pressure pattern of the writingoperation. The top of the underlying sheet is coated or impregnated witha material reactant with the chromogenic material, e.g., an acid clay oran acidic phenolic polymer material; and capsules are present on theoverlying or base-sheet which capsules contain a liquid solution ofchromogenic material. In another embodiment of the record material, thecapsules can contain the polymeric phenolic material in liquid solutionand the receiving surface of the underlying sheet can be supplied withthe chromogenic material.

It is possible to incorporate the chromogenic material in a solid,crystalline state in a binder material so that the chromogenic materialcan be transferred from the over lying sheet, upon the application ofpressure, to deposit some of the chromogenic material on the receivingsurface of the undersheet, which receiving surface carries acolor-activating polymeric material. Preferably, the chromogenicsubstance is dissolved in an appropriate solvent and minute droplets ofthe solution of the chromogenic material are encapsulated in minute,rupturable, capsules. It is apparent that many other arrangements arepossible, including different configurations and relationships of thesolvent and all of the mark-forming materials with respect to theirencapsulation and location on the supporting underlying or overlyingsheets or webs can be envisioned. Such arrangements are thoroughlydescribed in application for Letters Patent No. 392,404, filed Aug. 27,1964, in the names of Robert E. Miller and Paul S. Phillips, Jr. nowabandoned.

The polymeric mark-forming components have a common solubility with thenovel chromogenic material in at least one liquid solvent when theacid-reacting material is a phenolic or other acidic organic polymer. Ina single system, several chromogenic materials can be used with the sameor different polymeric materials. Several polymeric materials can bereactively contacted with a single chromogenic compound or with amixture of chromogenic compounds.

The solvent can be maintained in physical isolation in minute dropletsuntil such time as it is released by application of pressure. This maybe accomplished by several known techniques, but, preferably, isolationis maintained by encapsulation of individual droplets of the solvent ina microcapsule according to the procedures described, for example, inUS. Pat. No. 2,712,507, issued July 5, 1955 on the application ofBarrett K. Green; 2,730,457, issued Jan. 10, 1956 on the application ofBarrett K. Green and Lowell Schleicher; 2,800,457, issued July 23, 1957on the application of Barrett K. Green and Lowell Schleicher; 2,800,458,issued July 23, 1957 on the application of Barrett K. Green, re-issuedas Re. Pat. No. 24,899 on Nov. 29, 1960; and 3,041,289 issued June 26,1962 on the application of Bernard Katchen and Robert E. Miller. Themicroscopic capsules, when disposed within or upon a supporting web as amultiplicity in continguous juxtaposition, are rupturable by pressure,such as normal marking 4 pressure found, for example in writing ortyping operations.

The material or materials chosen as the wall material for thedroplet-containing microcapsules, in addition to being pressurerupturable, are inert or unreactive with respect to the intendedcontents of the capsules and other mark-forming components so that thecapsule wall material remains intact under normal storage conditionsuntil such time as it is released by an application of marking pressure.Preferred examples of eligible capsule wall materials include gelatin,gum arabic and many others thorouhly described in the aforementionedpatents.

For most uses in record material, the capsule size does exceed about 50microns in diameter. Preferably, the capsules are smaller than about 15microns in diameter.

The acidic organic polymeric material useful for developing the color ofnovel chromogenic compounds in this invention include phenolic polymers,phenol acetylene polymers, maleic acid-rosin resins, parially or whollyhydrolyzed styrene-maleic anhydride copolymers and ethylene-maleicanhydride copolymers, carboxy polymethylene and wholly or partiallyhydrolyzed vinylmethylethermaleic anhydride copolymer and mixturesthereof.

More specifically, phenol polymers found useful include alkyl-phenolacetylene resins, which are soluble in common organic solvents andpossess permanent fusibility in the absence of being treated bycross-linking materials. Another specific group of useful phenolicpolymers are members of the type commonly referred to as novolacs, (atype of phenol-formaldehyde polymeric material) which are characterizedby solubility in common organic solvents and which are, in the absenceof cross-linking agents, permanently fusible. Resol resins if they arestill soluble, can be used, though they are subject to change inproperties upon aging. Generally, phenolic polymer material found usefulin practicing this invention is characterized by the pressure ofhydroxyl groups and by the absence of groups such as methylol, whichtend to promote infusibility or cross-linking of the polymer, and,further, by being soluble in inorganic solvents and relatively insolublein aqueous media. Mixtures of these organic polymers and other acidicmaterials can be employed.

A laboratory method useful in the selection of suitable phenolic resinsis the determination of the infrared absorption pattern. -It has beenfound that phenolic resins which undergo absorption in the 3200-3500cm.- region (which is indicative of hydroxyl groups) on the resinmolecules and which do not absorb in the 1600-1700 cm. region areeligible. This latter absorption region is indicative of desensitizationof hydroxyl groups which desensitization renders such groups unavailablefor reaction with the chromogenic materials.

The preparation of some organic polymeric materials useful forpracticing this invention has been described in Industrial andEngineering Chemistry, volume 43, pages 134 to 141, January 1951, and aparticular polymer thereof is described in Example I of US. Pat. No.2,052,093, issued to Herbert Honel on Aug. 25, 1936. The preparation ofthe phenol-acetylene polymers has been described in Industrial andEngineering Chemistry, volume 41, pages 73 to 77, January 1949. Thepreparation of maleic anhydride copolymers is described in theliterature, such as, for example, one of the maleic anhydride vinylcopolymers, as disclosed in Vinyl and Related Polymers, by Calvin E.Schildknecht, second printing, published April 1959, by John Wiley &Sons, Incorporated: See pages to 68 (styrene-maleic anhydridecopolymer), 530 to 531 (ethylene-maleic anhydride copolymer), and 628 to630 (vinylmethylether-maleic anhydride copolymer).

When the acidic material used as a mark-forming component in the presentinvention is one of the aforementioned organic polymers, the liquidsolvent is chosen so as to be capable of dissolving it. The solvent canbe volatile or nonvolatile, and a singleor multiple-component solventcan be used which is wholly or partially volatile. Examples of volatilesolvents useful in practicing the present invention include toluene,petroleum distillate, perchloroethylene, and xylene. Examples ofnonvolatile solvents include high-boiling-point petroleum fractions andchlorinated biphenyls. Generally, the solvent chosen is capable ofdissolving at least about 0.3 percent, by weight, of the chromogenicmaterial, and at least about 3 to 5 percent, by weight, of the acidicpolymeric material. However, in the preferred system, the solvent iscapable of dissolving an excess of the polymeric material.

Further, the solvent does not interfere with the markforming reaction.In some instances, the presence of the solvent has been found tointerfere with the mark-forming reaction or diminish the intensity ofthe mark. In these instances the solvent chosen should be sufficientlyvolatile to assure its removal from the reaction site soon after havingbrought the mark-forming components into reactive contact so that themark-forming reaction can proceed.

Since the mark-forming reaction requires that an intimate mixture of thecomponents be brought about through solution of said components, one ormore of the markforming components can be dissolved in solvent dropletsisolated by encapsulation, the only requirement being that at least oneof the components essential to the mark-forming reaction be maintainedisolated until the mank-forming reaction is desired.

In the usual case, the mark-forming components are so chosen as toproduce a mark upon application of pressure to a coated system of sheetsat room temperature to degrees centigrade). However, the presentinvention also includes a system wherein the solvent component is notliquid at temperatures near room temperature but is liquid and incondition for forming solutions only at elevated temperatures.

The support sheet member on which components of the system are disposedcan comprise a single or a dual sheet assembly. In the case where allcomponents are disposed on a single sheet, the record material isreferred to as a self-contained or autogenous system. Where there is amigration of solvent, with or without the mark-forming component, fromone sheet to another, the record material is referred to as a transfersystem. (Such a system may also be referred to as a two-fold system, inthat at least two sheets are required and each sheet includes acomponent, or components, essential to the mark-forming reaction.) Wherean adequate amount of the colored reaction product is produced in liquidor dissolved form on a surface of one sheet, a colored mark can berecorded on a second sheet by transfer of the colored reaction product.

(In a preferred case, where microcapsules are employed, they can bepresent in the sheet support material either disposed therethroughout oras a coating thereon, or both. The capsules can be applied to the sheetmaterial as a dispersion in the liquid vehicle in which they weremanufactured, or, if desired, they can be separated from the vehicle andthereafter dispersed in a solution of the acidreacting polymericcomponent (for instance, grams of water and 53 grams of a 1 percent, byweight, aqueous solution of polyvinylmethylether-maleic anhydride) toform a sheet-coating composition in which, because of the inertness ofthe solution and the capsulm, both components retain their identity andphysical integrity. When this composition is disposed as a film on thesupport material and dried, the capsules are held therein subject torelease of the contained liquid by rupture of the capsule walls. Thelatter technique, relying on the inertness of the microcapsule and thedispersing medium of the filmforming mark-forming polymeric component,provides a method for preparing a sensitive record material coatinghaving the capsules interspersed directly in a dry film of the polymericmaterial as the film is laid down from solution. A further alternativeis to disperse one or more mark-forming components, and thechromogenic-materialcontaining microcapsules in a liquid medium not asolvent for either the mark-forming component or the microcapsules, withthe result that all components of the markforming system can be disposedon or within the support sheet in the one operation. The severalcomponents can be applied individually. The capsules also can be coatedonto a sheet as a dispersion in a solution of polymeric material whichis not necessarily reactive with the capsulecontained solution ofchromogenic materials.

The respective amounts of the several components can be varied accordingto the nature of the materials and the architecture of the recordmaterial unit desired or required. Suitable lower amounts include, inthe case of the chromogenic material, about 0.005 to 0.075 pound perream (a ream in this application meaning five hundred (500) sheets of25" x 38" paper, totalling 3,300 square feet); in the case of thesolvent, about 1 to 3 pounds per ream; and in the case of the polymer,about 0.5 pounds per ream. In all instances, the upper limit isprimarily a matter of economic consideration.

The slurry of capsules can be applied to a wet web of paper, forexample, as it exists on the screen of a Fourdrinier paper machine, soas to penetrate the paper web a distance depending on the freeness ofthe pulp and the water content of the web at the point of application.The capsules can be placed directly in or on a paper or support sheet.Not only capsule structures, but continuous films which contain amultitude of microscopic, unencapsulated, droplets for local release inan area subjected to pressure can be utilized. (See, for example, US.Pat. No. 2,299.694 which issued Oct. 20, 1942, on the application ofBarrett K. Green.)

With respect to the acidic organic polymeric component, a solutionthereof in an evaporable solvent can be introduced into an amount ofwater and the resulting mixture can be agitated while the evaporablesolvent is blown off by an air blast. This operation leaves an aqueouscolloidal dispersion slurry of the polymeric material, which can beapplied to finished paper so as to leave a surface residue or the slurrycan be applied to a wet web of paper or at the size-press station of apaper making machine. In another method for making a polymer-sensitizedsheet, the water-insoluble polymer can be ground to a desired orrequired particle size in a ball mill with water, preferably with adispersing agent, such as a small quantity of sodium silicate. If abinder material of hydrophilic properties is ground with the polymericmaterial, the binder itself can act as a dispersant. If desired, anamount of binder material of up to 40 percent, by weight, of the amountof polymeric material can be added to the ball-milled slurry of-materialssuch binder materials being of the .paper coating binderclass, including, for example, gum iar-abic, casein,hydroxyethylcellulose, and latexes (such as styrene-butadienecopolymer). If desired, oil absorbents in the form of fullers earth canbe combined with the polymeric material particles to assist inretaining, in situ, the liquid droplets of chromogenic material solutionto be transferred to it in data-representing configuration, for thepurpose of preventing bleeding of the print.

Another method for applying the chromogenic or polymeric materialindividually to a single sheet of paper is by immersing a sheet of paperin 1-10 percent, by weight, solution of the material in an evaporablesolvent. This operation is conducted individually for each reactant,because if the other reactant materials are present, contact of thereactants results in a premature coloration over the sheet area. A driedsheet with one component then can be coated with a solution of anothercomponent, the solvent of which is a non-solvent to the already-suppliedcomponent.

The polymeric material can also be dissolved in ink composition vehiclesto form a printing ink of colorless character and can be used tospot-print a proposed record-sheet-unit sensitized for recording, in areactionproduced color in those spot-printed areas, by application of asolution of the chromogenic material. In the case of phenolic polymer, aprinting ink can be made of up to 75 percent, by weight, of the phenolicpolymeric material in a petroleum-based solventthe ink being built to aviscosity suitable for printing purposes. The relative amounts ofreactive, mark-forming, components to be used in practice of thisinvention, are those most convenient and economical amounts consistentwith adequate, desired or required visibility of the recorded data. Theresolution of the recorded data is dependent on, among other things,particle or capsule size, distribution and amount of particles orcapsules, liquid solvent migration, chemical reaction efficiency, andother factors, all of which can be optimized empirically by one skilledin the art.

In the color system of this invention the acidic markforming materialreacts with the chromogenic material to effect distinctive colorformation or color change. In a multi-sheet system in which an acidicorganic polymer is employed, other materials to supplement the polymerreactants can be included. For example, kaolin can be added to improvethe transfer of the liquid and/or the dissolved materials between thesheets. In addition, other materials such as bentonite, attapulgite,talc, feldspar, halloysite, magnesium trisilicate, silica gel,pyrophyllite, zinc sulfate, calcium sulfate, calcium citrate, calciumphosphate, calcium fluoride, barium sulfate and tannic acid can beincluded.

Various methods known to the prior art and others disclosed in theaforementioned application Ser. No. 392,404 in the names of Miller etal. now abandoned and in US. patent application Ser. No. 420,193 in thenames of Phillips et al. now US. Pat. 3,455,721 can be employed incompositions useful for coating mark-forming materials into supportingsheets. An example of the compositions which can be coated onto thereceiving surface of an underlying sheet of a multi-sheet to react witha capsule coating on the underside of an overlying sheet is as follows:

Coating composition: Percent by weight Phenolic polymer mixture 17 Papercoating kaolin (white) 57 Calcium carbonate 12 Styrene butadiene latex 4Ethylated starch 8 Gum arabic 2 Having disclosed, generally, thechromogenic materials of this invention and preferred methods forutilizing the chromogenic materials, in combination with othermaterials, as reactive components in mark-forming record material;examples now are disclosed further illustrating the chromogenicmaterials.

8 EXAMPLE -I The synthesis of l c1 |::o 01 O ll C $H3 Cal? Q N CH wascarried out by admixing 9.02 grams of C2115 01 N/ I COOH OH CZHS c1 and2.44 grams of 0H,- CH

in ml. of sulfuric acid specific gravity 1.72) and heating at C. for 45minutes. Heating was continued at C. for an additional 3 hours. Themixture then was cooled and poured into 500 grams of ice. The pH of themixture then was adjusted to a pH of 10 to 11 by the addition of 50percent sodium hydroxide. The mixture was extracted with three 100 ml.portions of benzene. After two washings with 10 percent sodiumhydroxide, the mixture was washed with water until neutral. Afterevaporation to a low volume crystallization was carried out frompetroleum ether. Recrystallization from benzene ether resulted in ayield of 60 weight percent. The product exhibited a red color on clayand had a melting point of 253-254 C.

Analysis was as follows: Calculated (percent): C, 58.12; H, 3.94; N,2.60; Cl, 26.39. Found (percent): C, 58.04; H, 4.01; N, 2.52; CI, 26.21.

EXAMPLE II The following compounds were prepared under the sameconditions and according to the procedure described in Example I.

Reactant I Reactant II Resulting Dye 1 COOH OH C2115 Cl OH TABLEIC0ntinued React ant I Reactant II Resulting Dye 01 CH1 G1 I 1 Cl 0 CH9,OH 01 C=O C2H5 01 c1 0 COOH O C H I 2 s I 3 Same as above Cl CH -OH I 11 The color on clay and the melting point for the resulting dyes are asfollows:

Color on clay: Melting point, C.

(1) Red 268-269. (2) Red 251-252. (3) Red 236-237. (4) Red 250-251. (5)Red Not determined. (6) Red 229-230.

Example III The compounds of this invention exhibit good faderesistance. For example, a drawdown on different coated sheets was madefrom a 0.5 percent solution in benzene on the following compounds:

After printing, the sheets were exposed to a daylight box for 20 hours.The results were as follows:

(a) 1/10 at start I/Iu at end Kaolin Koalin phenol Clay phenol ClayNo'm.-(a)I/Io is the intensity of color over the intensity of thebackground. A value of 100 would indicate a white color. Therefore, theless color present the higher the value.

Not only does the tetrachloronated compound exhibit good faderesistance, but it also improves on the degree of change or fade whencompared to the unchloronated compound. The A in 1/1 for the abovedrawdowns was as follows:

Cl C 1'1 /N R3 01115 O wherein each R R R or R is hydrogen, an alkylradical having 1 to 4 carbon atoms or chlorine and at least one of saidR groups is an alkyl radical or chlorine.

2. A compound according to claim 1 wherein each R R R or R is hydrogen,methyl or chlorine.

References Cited UNITED STATES PATENTS 3,501,331 3/1970 Kimwa et a1.260-3433 ALEX MAZEL, Primary Examiner A. M. T. TIGHE, Assistant ExaminerU.S. Cl. X.R. 1l736.8, 36.2

